scholarly journals Erythropoietin Decreases the Occurrence of Myocardial Fibrosis by Inhibiting the NADPH-ERK-NF-κB Pathway

Cardiology ◽  
2015 ◽  
Vol 133 (2) ◽  
pp. 97-108 ◽  
Author(s):  
Li-Ping Wang ◽  
Xiu-Hong Yang ◽  
Xiao-Jun Wang ◽  
Shu-Min Li ◽  
Na Sun ◽  
...  

Objectives: The aim of this study was to investigate the protective role of erythropoietin (EPO) against myocardial fibrosis (MF). Methods: Pressure-overloaded rats were established by abdominal aortic constriction, the rats were randomly divided in a double-blind manner into 3 groups (n = 12 for each group): sham-operated rats (sham), operated rats receiving physiological saline (vehicle) and operated rats receiving 4,000 U/kg rhEPO (EPO group). The vehicle and drugs were administered to rats by intraperitoneal injection. In addition, cultured adult rat cardiac fibroblasts (CFs) were utilized to investigate the role of EPO in CF proliferation and collagen secretion. Results: After 4 weeks, besides an increase in blood pressure, myocardial hypertrophy, collagen deposition in the myocardium and decreased cardiac function were observed in the pressure-overloaded rats. The expression of NADPH oxidase (Nox2 and Nox4) and inflammatory cytokines (CD45, F4/80 and MCP-1) was also significantly increased. All these alterations were prevented by EPO. TGF-ß promoted CF proliferation, collagen secretion, ROS production and Nox2/Nox4 expression, which was inhibited by EPO. In addition, the TGF-ß-induced increase of ERK1/2 phosphorylation and NF-κB expression were attenuated by EPO. Conclusion: EPO inhibited rat MF induced by pressure overload and improved myocardial function by decreasing CF proliferation and differentiation via inhibition of the NADPH-ERK-NF-κB pathway.

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Norimichi Koitabashi ◽  
Masahiko Kurabayashi ◽  
Eiki Takimoto ◽  
David A Kass

[Background] Emerging evidence from cell-specific conditional gene manipulation models has revealed complex interactions with differential roles of cardiomyocyte (CM) and non-CM signaling in the evolution of pathological cardiac remodeling. A major factor involved in such cross talk is transforming growth factor-beta (TGFβ), which exists in CM,fibroblasts, and vascular cells. Both mechanical overload and prolonged catecholamine stimulation are critical determinants of hypertensive heart disease. Here, we tested the role of cell-specific TGFβ signaling in chronic pressure-overload or isoproterenol (Iso)-induced cardiac remodeling using CM-specific gene suppression of TGFβ type2 receptor in mice. [Methods and Results] αMHC-driven tamoxifen-inducible Cre (MCM) x Tgfbr2 floxed mice (MCMR2), which achieved CM-specific knockdown of TGFβ signaling, showed a striking suppression of cardiac dilatation and dysfunction induced by chronic pressure-overload. Chronic Iso infusion induced modest cardiac hypertrophy with moderate myocardial fibrosis. Interestingly, in contrast to TAC, myocardial fibrosis induced by the chronic Iso exposure was not inhibited, rather worsened in MCMR2 mice. Systemic treatment with TGFβ neutralizing antibody (NAb) for Chronic Iso significantly inhibited myocardial fibrosis, yet cardiac function and hypertrophy were not improved. In Iso-treated cultured cardiomyocytes, profibrotic genes were up-regulated by TGFβ-receptor inhibition, while they were inhibited in cultured cardiac fibroblasts. [Conclusion] CM-specific TGFβ signaling inhibition has marked protective effect for pressure-overload induced cardiac remodeling but not for Iso-induced cardiac remodeling. These results suggest that the role of TGFβ signaling may be determined by targeted cell types and pathological stresses in a development of heart failure.


2016 ◽  
Vol 38 (6) ◽  
pp. 2103-2122 ◽  
Author(s):  
Peng Deng ◽  
Ling Chen ◽  
Zheng Liu ◽  
Ping Ye ◽  
Sihua Wang ◽  
...  

Background/Aims: Cardiac fibrosis is the primary cause of deteriorated cardiac function in various cardiovascular diseases. Numerous studies have demonstrated that microRNAs (miRNAs) are critical regulators of myocardial fibrosis. Specifically, many studies have reported that miR-150 is downregulated in cardiovascular diseases, such as acute myocardial infarction (AMI), myocardial hypertrophy and myocardial fibrosis. However, the exact role of miR-150 in these pathological processes remains unknown. Methods: We used the transverse aortic constriction (TAC) mouse model to study the role of miR-150 in cardiac fibrosis induced by pressure overload. After the TAC operation, qRT-PCR was used to measure the expression profiles of miR-150 in left ventricle tissues and populations of primary heart cell types. Then, we used both miR-150 knockout mice and wild type (WT) mice in the TAC model. Changes in cardiac function and pathology were measured using transthoracic echocardiography and pathological analysis, respectively. Furthermore, we predicted the target of miR-150 in cardiac fibroblasts (CFs) and completed in vitro CF transfection experiments using miR-150 analogs and siRNA corresponding to the predicted target. Results: We observed decreased expression levels of miR-150 in hearts suffering pressure overload, and these levels decreased more sharply in CFs than in cardiomyocytes. In addition, the degrees of cardiac function deterioration and cardiac fibrosis in miR-150-/- mice were more severe than were those in WT mice. By transfecting CFs with an miR-150 analog in vitro, we observed that miR-150 inhibited cardiac fibroblast activation. We predicted that the transcription factor c-Myb was the target of miR-150 in CFs. Transfecting CFs with c-Myb siRNA eliminated the effects of an miR-150 inhibitor, which promoted CF activation. Conclusion: These findings reveal that miR-150 acts as a pivotal regulator of pressure overload-induced cardiac fibrosis by regulating c-Myb.


2020 ◽  
Vol 134 (1) ◽  
pp. 71-72
Author(s):  
Naseer Ahmed ◽  
Masooma Naseem ◽  
Javeria Farooq

Abstract Recently, we have read with great interest the article published by Ibarrola et al. (Clin. Sci. (Lond.) (2018) 132, 1471–1485), which used proteomics and immunodetection methods to show that Galectin-3 (Gal-3) down-regulated the antioxidant peroxiredoxin-4 (Prx-4) in cardiac fibroblasts. Authors concluded that ‘antioxidant activity of Prx-4 had been identified as a protein down-regulated by Gal-3. Moreover, Gal-3 induced a decrease in total antioxidant capacity which resulted in a consequent increase in peroxide levels and oxidative stress markers in cardiac fibroblasts.’ We would like to point out some results stated in the article that need further investigation and more detailed discussion to clarify certain factors involved in the protective role of Prx-4 in heart failure.


2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Prachi Umbarkar ◽  
Sultan Tousif ◽  
Anand P Singh ◽  
Joshua C Anderson ◽  
qinkun zhang ◽  
...  

Background: Myocardial fibrosis contributes significantly to heart failure (HF). Fibroblasts are among the predominant cell type in the heart and are primary drivers of fibrosis. To identify the kinases involved in fibrosis, we analyzed the kinome of mouse cardiac fibroblasts (CF) isolated from normal and failing hearts. This unbiased screening revealed the critical role of the GSK-3 family-centric pathways in fibrosis. Previously we have shown that among two isoforms of GSK3, CF-GSK3β acts as a negative regulator of fibrosis in the injured heart. However, the role of CF-GSK3α in the pathogenesis of cardiac diseases is completely unknown. Methods and Results: To define the role of CF-GSK3α in HF, we employed two novel fibroblast-specific KO mouse models. Specifically, GSK3α was deleted from fibroblasts or myofibroblasts with tamoxifen-inducible Tcf21- or periostin- promoter-driven Cre recombinase. In both models, GSK3α deletion restricted pressure overload-induced cardiac fibrosis and preserved cardiac function. We examined the effect of GSK3α deletion on myofibroblast transformation and pro-fibrotic TGFβ1-SMAD3 signaling in vitro . A significant reduction in cell migration, collagen gel contraction, and α-SMA expression in TGFβ1-treated KO CFs confirmed that GSK3α is required for myofibroblast transformation. Surprisingly, GSK3α deletion did not affect SMAD3 activation, indicating the pro-fibrotic role of GSK3α is SMAD3 independent. To further delineate the underlying mechanisms, proteins were isolated from CFs of WT and KO mice at 4 weeks post-injury, and kinome profiling was performed. The kinome analysis identified the downregulation of RAF family kinase activity in KO CFs. Moreover, mapping of significantly altered kinases against literature annotated interactions generated ERK-centric networks. Consistently, flow cytometric analysis of CFs confirmed significantly low levels of pERK in KO mice. Additionally, our in vitro studies demonstrated that GSK3α deletion prevents TGFβ1-induced ERK activation. Interestingly, IL-11, a pro-fibrotic downstream effector of TGFβ1, was remarkably reduced in KO CFs and ERK inhibition further decreased IL-11 expression. Taken together, herein, we discovered the GSK3α-ERK-IL-11 signaling as a critical pro-fibrotic pathway in the heart. Strategies to inhibit this pro-fibrotic network could prevent adverse fibrosis and HF. Conclusion: CF-GSK3α plays a causal role in myocardial fibrosis that could be therapeutically targeted for future clinical applications.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Ludovic O Bénard ◽  
Daniel S Matasic ◽  
Mathilde Keck ◽  
Anne-Marie Lompré ◽  
Roger J Hajjar ◽  
...  

STromal Interaction Molecule 1 (STIM1), a membrane protein of the sarcoplasmic reticulum, has recently been proposed as a positive regulator of cardiomyocyte growth by promoting Ca2+ entry through the plasma membrane and the activation of Ca2+-mediated signaling pathways. We demonstrated that STIM1 silencing prevented the development of left ventricular hypertrophy (LVH) in rats after abdominal aortic banding. Our aim was to study the role of STIM1 during the transition from LVH to heart failure (HF). For experimental timeline, see figure. Transverse Aortic Constriction (TAC) was performed in C57Bl/6 mice. In vivo gene silencing was performed using recombinant Associated AdenoVirus 9 (AAV9). Mice were injected with saline or with AAV9 expressing shRNA control or against STIM1 (shSTIM1) (dose: 1e+11 viral genome), which decreased STIM1 cardiac expression by 70% compared to control. While cardiac parameters were similar between the TAC groups at weeks 3 and 6, shSTIM1 animals displayed a progressive and total reversion of LVH with LV walls thickness returning to values observed in sham mice at week 8. This reversion was associated with the development of significant LV dilation and severe contractile dysfunction, as assessed by echography. Hemodynamic analysis confirmed the altered contractile function and dilation of shSTIM1 animals. Immunohistochemistry showed a trend to more fibrosis. Despite hypertrophic stimuli, there was a significant reduction in cardiac myocytes cross-section area in shSTIM1-treated animals as compared to other TAC mice. This study showed that STIM1 is essential to maintain compensatory LVH and that its silencing accelerates the transition to HF.


2015 ◽  
pp. 325-334 ◽  
Author(s):  
W. LIU ◽  
X. WANG ◽  
Z. MEI ◽  
J. GONG ◽  
X. GAO ◽  
...  

Stress serves as a risk factor in the etiology of hypertension. The present study was designed to decipher the effect and mechanism of chronic stress on the progression of pressure overload-induced cardiac dysfunction. We used abdominal aortic constriction (AAC) to induce pressure overload with or without chronic restraint stress to establish the animal models. Echocardiographic analysis showed pressure overload-induced cardiac dysfunction was worsened by chronic stress. Compared with the AAC rats, there is a significant increase in cardiac hypertrophy, injury, apoptosis and fibrosis of the AAC + stress rats. Furthermore, we found the secretion of norepinephrine (NE) increased after the AAC operation, while the level of NE was higher in the AAC + stress group. Cardiomyocytes and cardiac fibroblasts isolated from neonatal rats were cultured and separately treated with 1, 10, 100 μM NE. The higher concentration NE induced more cardiomyocytes hypertrophy and apoptosis, cardiac fibroblasts proliferation and collagen expression. These results revealed that high level of NE-induced cardiomyocytes hypertrophy and apoptosis, cardiac fibroblasts proliferation and collagen expression further contributes to the effect of chronic stress on acceleration of pressure overload-induced cardiac dysfunction.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10502
Author(s):  
Huan Guo ◽  
Xinke Zhao ◽  
Haixiang Su ◽  
Chengxu Ma ◽  
Kai Liu ◽  
...  

Background Radiation exposure of the thorax is associated with a greatly increased risk of cardiac morbidity and mortality even after several decades of advancement in the field. Although many studies have demonstrated the damaging influence of ionizing radiation on cardiac fibroblast (CF) structure and function, myocardial fibrosis, the molecular mechanism behind this damage is not well understood. miR-21, a small microRNA, promotes the activation of CFs, leading to cardiac fibrosis. miR-21 is overexpressed after irradiation; however, the relationship between increased miR-21 and myocardial fibrosis after irradiation is unclear. This study was conducted to investigate gene expression after radiation-induced CF damage and the role of miR-21 in this process in rats. Methods We sequenced irradiated rat CFs and performed weighted correlation network analysis (WGCNA) combined with differentially expressed gene (DEG) analysis to observe the effect on the expression profile of CF genes after radiation. Results DEG analysis showed that the degree of gene changes increased with the radiation dose. WGCNA revealed three module eigengenes (MEs) associated with 8.5-Gy-radiation—the Yellow, Brown, Blue modules. The three module eigengenes were related to apoptosis, G2/M phase, and cell death and S phase, respectively. By blocking with the cardiac fibrosis miRNA miR-21, we found that miR-21 was associated with G2/M blockade in the cell cycle and was mainly involved in regulating extracellular matrix-related genes, including Grem1, Clu, Gdf15, Ccl7, and Cxcl1. Stem-loop quantitative real-time PCR was performed to verify the expression of these genes. Five genes showed higher expression after 8.5 Gy-radiation in CFs. The target genes of miR-21 predicted online were Gdf15 and Rsad2, which showed much higher expression after treatment with antagomir-miR-21 in 8.5-Gy-irradiated CFs. Thus, miR-21 may play the role of fibrosis and G2/M blockade in regulating Grem1, Clu, Gdf15, Ccl7, Cxcl1, and Rsad2 post-irradiation.


Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Francisco J Rios ◽  
ZhiGuo Zou ◽  
Karla B Neves ◽  
Sarah S Nichol ◽  
Livia L Camargo ◽  
...  

TRPM7 has cation channel and kinase properties, is permeable to Mg 2+ , Ca 2+ , and Zn 2+ and is protective in the cardiovascular system. Hyperaldosteronism, which induces hypertension and cardiovascular fibrosis, is associated with Mg 2+ wasting. Here we questioned whether TRPM7 plays a role in aldosterone- induced hypertension and fibrosis and whether it influences cation regulation. Wild-type (WT) and TRPM7-deficient (M7+/Δ) mice were treated with aldosterone (600μg/Kg/day) and/or 1% NaCl (drinking water) (aldo, salt or aldo-salt) for 4 weeks. Blood pressure (BP) was evaluated by tail-cuff. Vessel structure was assessed by pressure myography. Molecular mechanisms were investigated in cardiac fibroblasts (CF) from WT and M7+/Δ mice. Protein expression was assessed by western-blot and histology. M7+/Δ mice exhibited reduced TRPM7 expression (30%) and phosphorylation (62%), levels that were recapitulated in WT aldo-salt mice. M7+/Δ exhibited increased BP by aldo, salt and aldo-salt (135-140mmHg) vs M7+/Δ-veh (117mmHg) (p<0.05), whereas in WT, BP was increased only by aldo-salt (134mmHg). Mesenteric resistance arteries from WT aldo-salt exhibited increased wall/lumen ratio (80%) and reduced internal diameter (15%) whereas vessels from M7+/Δ exhibited thinner walls by reducing cross-sectional area (35%) and increased internal diameter (23%) after aldo-salt. Aldo-salt induced greater collagen deposition in hearts (68%), kidneys (126%) and aortas (45%) from M7+/Δ vs WT. Hearts from M7+/Δ veh exhibited increased TGFβ, IL-11 and IL-6 (1.9-fold), p-Smad3 and p-Stat1 (1.5-fold) whereas in WT these effects were only found after aldo-salt. Cardiac expression of protein phosphatase magnesium-dependent 1A (PPM1A), a Mg 2+ -dependent phosphatase, was reduced (3-fold) only in M7+/Δ mice. M7+/Δ CF showed reduced proliferation (30%) and PPM1A (4-fold) and increased expression of TGFβ, IL-11 and IL-6 (2-3-fold), activation of Stat1 (2-fold), Smad3 (9-fold) and ERK1/2 (8-fold) compared with WT. Mg 2+ supplementation normalized cell proliferation and reduced protein phosphorylation in M7+/Δ CF (p<0.05). Our findings indicate a protective role of TRPM7 in aldosterone-salt induced cardiovascular injury through Mg 2+ -dependent mechanisms.


2021 ◽  
Vol 152 ◽  
pp. 1-16
Author(s):  
Haifeng Yin ◽  
Amanda J. Favreau-Lessard ◽  
Joanne T. deKay ◽  
Yodit R. Herrmann ◽  
Michael P. Robich ◽  
...  

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